The Rock’n’Rolla way

My-self and Gary began thinking of building a boat between us about ten years ago. I drew some ideas of a basic cuddy fishing boat with a hull based loosely on Gary’s wooden boat. We chose Gary’s flat chine deep v planing hull design because we knew it performed well at sea and would accept inboard or outboard engine variants.
We planned to construct a basic mould, from which we would build a boat each in fibreglass, the boat would be a pretty simple construction of moulded hull and ring deck/cuddy with a plywood deck bonded in.
We started to build a large shed on Gary’s drive to do the construction work, but soon ran into problems with his neighbours.
In the mean time I had built the frames required to form the wooden mock up of our hull mould.
Our project stalled for a couple of years due to other commitments, going fishing, lack of finance and going to the pub etc.

The desire to carry on however never went away and we were eventually joined in the project by John and Paul.
John made room for our project in a corner of his work premises and we set about arranging the hull frames in Xmas week 2005.
My-self and John had our trade experience to apply to the construction, but none of us had any experience of working with fibreglass. We would all go through a huge learning curve and make plenty of mistakes on the way. Some of our cock ups were pretty costly and time consuming (good job it was only a hobby).

We were all able to bring individual skills to the table, I would draw our designs and make wooden plugs, John would cut wood and entertain us with stories, Gary would send Paul to brew up and go to the shop, Paul would brew up and go to the shop.

If I were to go into every detail of our construction method you would be reading a book, not this short introduction.
So the basics of this project are as follows. First decide what you want to build, we had decided on an 18 foot deep v sports fisher, with enclosed overnight cuddy, self draining un-cluttered deck able to take 220 horsepower in either inboard or outboard engine form.
I was able to draw and design the boat using a 2D shareware CAD programme down loaded for free off the internet.
The design of the hull and super structure GRP layup must be matched to the boats intended use and performance.
The laminate design for our project was arrived at by following rules and calculations as laid out in a book by Dave Gerr entitled “The Elements of Boat Strength”.
The hull and super structure of our boat is built using 450 gm chopped strand matt and 300gm woven roving bonded with polyester resin and a finishing gell coat in appropriate thickness to the design requirement of each component.
The boat has a hull design speed of 50 knots.
A far cry from our original simple design the boat we built has 37 individual GRP components that come together to form the finished article.

Back to basics now, we need a mould from which to produce our craft. As said there are 37 different components required for the boat.
Building a mould to produce these components uses the same principle for all, whether you are making a ring deck mould or a simple hatch mould.
Accurate dimensions and angles must first be taken from your design drawings and full size wooden mock ups of the finished unit made.
Sticking to one material is a good rule of thumb to avoid your plug (wooden mock up) from moving or warping. MDF was our material of choice as it’s pretty stable and easy to work with.
Make sure all external edges are rounded off and use filler on internal edges sanded and smoothed to a quality finish.
Spray the wooden plug with a sealant and then layers of high build primer.
This can then be sanded back to a first class finish.
It is important to use polyester based paint systems so that you avoid any adverse reaction in the GRP later.
On large flat areas we bonded gloss formica onto MDF as an alternative to painting.
Once you have achieved a first class finish apply at least six coats of wax, polishing in between each coat.
To ensure your mould releases from the plug, apply release agent to the waxed plug.
You are now ready to apply the gell coat for the mould followed by between 8 and 10 layers of chopped strand matt.
If this is a large mould requiring strengtheners or turning rings, the mould must reach full cure before attaching these.
Pop the mould off the plug when cured, inspect for and repair any damage.
Make sure to buff the mould surface to a first class finish then apply at least six coats of wax to the mould surface. You are now ready to lay up your boat.

They say a picture paints a thousand words so here’s around 110,000 words worth of pictures for your perusal.

The boat was drawn on a free shareware CAD programme called Draft Choice for Windows.

Timber frames arranged to build the plug for the hull

Skin the hull plug in plywood, MDF or other suitable sheet material

The plug begins to take shape, foam lift strakes added etc. filled and sanded ready for painting

Hull plug sealed and high build primer applied

Swiftly moving on the hull plug has been buffed to a class A finish, six coats of wax applied, release agent applied, tooling gel coat for the mould its self applied followed by 10 layers of 450grm chopped strand matt

After curing for four weeks the turning rings and ply strengtheners are applied

Its time to lift the hull mould off the plug

Inspect the mould for any damage and repair if necessary

Once the mould is at a class A finish apply six coats of wax and a release coat (first moulding out only).
Here goe’s! Apply the gel coat for your hull followed by layers of chopped strand matt and woven roving to the required design thickness

Now add the transome board at this stage it’s the same process for inboard and outboard motors. The board is bedded in on two wet layers of chopped strand matt and clamped tight until the resin has cured. The board had been given three coats of resin before fitting and will be glassed in place with a further six layers of chopped strand. The target thickness for the transome is 52mm -53mm.
The board is fitted before the hull is released from the mould

Before lifting the hull from its mould, the GRP under floor matrix is fitted.
The same process is used to build the mould for the matrix as was for the hull.
To make sure the matrix fits, the plug and mould is constructed in a hull moulding.

MDF panels arranged to build the plug

Tooling gel applied for the mould

Mould laid up in situ

Matrix mould lifted out trimmed polished and ready to mould from

Matrix moulding released and trimmed ready to fit in the boat

Inboard engine beds also fitted at this stage

Matrix moulding lowered into place onto bedding compound and edges tabbed in with two layers of chopped strand

Time to release the hull from the mould

The main deck area and front and rear bulk heads are built as one moulding.
With large flat areas to work with the plug is made from MDF with gloss formica bonded onto it and exposed edges treated with varnish

The mould is now laminated in situ and strengtheners added.

The same process is used to build the internal cabin mould and all other small moulds Like cabin doors, hatch lids, buoyancy tanks etc.

By far the most intricate part of the build was the ring deck and cabin top. The MDF plug was built in nine sections on the bench before being assembled for striking a mould off.
Accurate dimensions were critical here, as it was not known if the top would fit the hull correctly until the completion of the plug, the laying up of the mould and the production of the first ring deck moulding.
Not only did the top need to match the contour of the hull it also had to marry in to the millimetre with, the under floor matrix, the front and rear bulk heads and the cut out for mounting the outboard engine.
Any slight discrepancy at this stage would be costly and take hours of work to rectify.
On finally releasing the ring deck moulding, fitting backing plates etc it was offered up to the hull for the first time and to huge relief it fitted perfectly!

Setting out the starboard side deck plug

Panelling out the port side ring deck plug

Building the motor well plug

Forming the front part of the cabin plug.

The plug for the wind shield

My garage full of plug parts for the ring deck including trestles on which to erect the ring deck plug as a whole

Let’s begin to put the ring deck plug components together.

Same old process, apply the high build primer ready to sand back and polish.

Wax the plug, apply the release agent and apply the tooling gel coat for the ring deck mould.

Build up layers of chopped strand matt to for the mould.

Release the mould from the plug, inspect for and repair any problems, wax the mould and prepare to lay up the top for the boat.

Offer the ring deck to the hull and secure temporarily with bolts, so that the top will always be in the same place as you lift the ring deck on and off while fitting the deck and bulk head positions.
In this photo the under floor buoyancy tanks can be seen.

Once all the main bits are bonded together and some basic fitting out done its time to let the nice new motor, see some day light.

It’s about now when your pocket really begins to hurt as you go for the final fit out.

This boat has been drifting around in my head for some time now and it’s a bit of a surreal moment when she finally hits the water.

WARNING!!! Do not try this at home it may cost you hair loss, bankruptcy and divorce. But you will be very pleased with the boat.